Firstly, yes, I am one of those people that is driven utterly mad by rattles... I know there are others out there like me!

I've been lurking here for a couple of weeks now having bought a low mileage 2006 330D SE around a month ago. From day one the car has had a dash rattle that the dealer I purchased it from has attempted to fix without success.

Some facts about said rattle:
> The rattle appears to be coming from the centre of the dash towards the windscreen, initially I thought it was the instrument cluster but I've felted this to no avail.
> The rattle gets (much) worse in colder weather and in hot weather (yes this is a relative concept in the UK) it appears to vanish. This morning at 10 degrees it was terrible.
> I have removed the top plastic vent cover in the centre of the dash this made no difference
> I have lubricated door seals and flock material (in case the sound is bouncing off interior) again no difference
> I have checked door runner plastic covers (in case the sound is bouncing off interior) again no difference

I've noticed that the plastic engine cover appears to be unevenly mounted. On the left-hand side it appears to be touching the strut mount, however on the right hand side it has some obvious clearance. I wonder if this could be the cause having read this. Is this unevenness normal?

Can I refit the front engine cover as per the second picture here without taking anything else off?

Have you tried padding the plastic trim on the front pillars. A guy at work has the same issue and it seem to be coming from the centre of the dash but the dealer tracked it down as being the plastic trim on the passenger windscreen pillar

i have the same car and my started to rattle, couldnt work out where at first but turned out it was the trim in the drivers footwell, was loose and bouncing up and down when going over uneven roads. Not sure yours is the same but worth a look. Get in the floorwell and tap around on the plastic trim.

I had this rattle turned out to be the auto wiper senser which is in the cover around the windscreen rear view mirror had come unstuck and rattling againts the inside of the cover. Glud it back in place rattle gone.

OK, so I reseated the engine cover last night. Definately wasn't fitted right. No noise this morning, but it appears to only happen when it is cooler so early days as it was pretty warm here this morning.

Next things I'll check will be:
> Drivers foot well trim
> Windscreen water sensor
> Plast trim on front pillars (is there an airbag in there I should be worried about if I start prying off trim?)

I've bought some plastic trim tools and felt so I'm armed and ready!

I've got the rear deck creak/pop to move onto after this, and also just fixed an exhaust rattle (as per here.)

Will update you guys in a couple oe days (provided its cold enough in the mornings)

OK, so no I'm stumped. The noise is 90% better so must be the engine cover but I've still got some noise left and whats left is the same noise... I've checked the engine cover and its definately fitted properly now.

One thing that did concern me when I refitted the cover was that the foam insulation underneath the cover had pretty much disintegrated. A couple of large pieces were OK but the majority of it was beyond help! It has all come away from the engine cover also. Maybe this is why I still have noise...?